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Articles 29941 - 29970 of 33373
Full-Text Articles in Entire DC Network
Analysis Of Retention In Supercritical Fluid Chromatography And Its Relation To Solubility, Z. Şermin Gönenç, Uğur Akman, Aydın K. Sunol
Analysis Of Retention In Supercritical Fluid Chromatography And Its Relation To Solubility, Z. Şermin Gönenç, Uğur Akman, Aydın K. Sunol
Turkish Journal of Chemistry
The effects of temperature, pressure and supercritical fluid density on the solubility-retention relationship of solutes in supercritical fluid chromatography are investigated. New retention data for naphthalene, phenanthrene, benzoic acid and 2-methoxy-naphthalene is obtained as a function of pressure at different temperatures. The bulk of the data is taken near the critical region of the mobile gas where the anomalities are expected. This data is used to compare two approaches for thermodynamic modeling of pressure dependence of solute retention. In these approaches, mobile-phase partial molar volumes of the solutes are determined either from bulk solubility data or from infinite-dilution fugacity coefficients. …
Quantum-Chemical Investigations On The Functionalized 1h-Pyrimidines, İsmail Yildirim, Makbule Tezcan, Yahya Güzel, Emin Saripinar, Yunus Akçamur
Quantum-Chemical Investigations On The Functionalized 1h-Pyrimidines, İsmail Yildirim, Makbule Tezcan, Yahya Güzel, Emin Saripinar, Yunus Akçamur
Turkish Journal of Chemistry
Conformational analysis and quantum-chemical calculations were carried out by means of the methods MMP2 and SCF MO LCAO in the CNDO/2 and MNDO approximation for the series of compounds being functionalized 1H- pyrimidines. The analysis of the electron density distribution depending on the substituents' nature was done on the basis of the data obtained.
Investigation Of Acid Sites On V_{2}O_{5}/Tio_{2}(A) Catalysts By Ftir With Adsorption Of Pyridine, Ahmet Akbaş, Holger Mi̇tzel, Dieter Höni̇ce
Investigation Of Acid Sites On V_{2}O_{5}/Tio_{2}(A) Catalysts By Ftir With Adsorption Of Pyridine, Ahmet Akbaş, Holger Mi̇tzel, Dieter Höni̇ce
Turkish Journal of Chemistry
The V_{2}O_{5}/TiO_{2}(A) catalysts were prepared by the grafting and their Br\"{o}nsted and Lewis acid sites were investigated with pyridine adsorption by using FTIR Spectroscopy. The results obtained showed that monolayer or less coverage of the surface of the support, TiO_{2}(A), took place up to V_{2}O_{5} content of 11.88 \%. When V_{2}O_{5} amount was higher then 11.88 \%, the support was covered as multilayer. Pyridine adsorption studies showed that the number of the Lewis acid sites of the V_{2}O_{5}/TiO_{2}(A) catalysts decreased with increasing of V_{2} O_{5} amount. The number of the Br\"{o}nsted acid sites increased with increasing V_{2}O_{5} content, reached a …
Poly (D,L-Lactic Acid) Homopolymers: Synthesis And Characterization, Xu Kaitian, Ahmet Kozluca, Emir B. Denkbaş, Erhan Pi̇şki̇n
Poly (D,L-Lactic Acid) Homopolymers: Synthesis And Characterization, Xu Kaitian, Ahmet Kozluca, Emir B. Denkbaş, Erhan Pi̇şki̇n
Turkish Journal of Chemistry
In this study, poly(D,L-lactic acid or D,L-lactide) (PDLLA) homopolymers were synthesized with different molecular weights. Low molecular weight PDLLAs (MW_n: 500-2300) were synthesized by direct polycondensation of DL-lactic acid without using any catalyst, while high molecular weight PDLLAs ( MW_n: 8x10^3-150x10^3) were produced by ring-opening polymerization of DL-lactide with stannous chloride as catalyst (initiator). Average molecular weights of PDLLAs were determined by end-group analysis, by viscosimetric measurements and by HPLC. PDLLA homopolymers were characterized by FTIR, NMR and DSC. In the production of PDLLAs by direct polymerization, molecular weights of the PDLLAs increased with the increase in the polymerization time …
Catalysis Of Autoxidation Of 2,6-Di-Tert-Butylphenol In Water By Metallophthalocyanine Tetrasulfonates Bound To Polyelectrolyte Supports, Yasemin Tura Kopkalli, Hayrettin Türk
Catalysis Of Autoxidation Of 2,6-Di-Tert-Butylphenol In Water By Metallophthalocyanine Tetrasulfonates Bound To Polyelectrolyte Supports, Yasemin Tura Kopkalli, Hayrettin Türk
Turkish Journal of Chemistry
2,6-and 2,10-Ionenes and soluble poly(vinylbenzyl)trimethylammonium chloride polyelectrolytes were synthesized and used as catalyst supports for cobalt-, iron- and copper-phthalocyanine tetrasulfonates on the autoxidation of 2,6-di-{\it tert}-butylphenol in water by molecular oxygen. Polyelectrolyte supported cobalt-phthalocyanine tetrasulfonate showed the highest activity in comparison with the supported analogous of iron- and copper-phthalocyanine tetrasulfonates. The supported metallophthalocyanine tetrasulfonates had better catalytic activities than the unsupported analogous for the reaction. The reaction yielded 3,3',5,5'-tetra-tert-butyl- 4,4'-diphenoquinone as the only oxidation product of 2,6-di-tert-butylphenol. The extent of the reaction was affected by time, temperature, pH, the types and concentrations of supports and metallophthalocyanine tetrasulfonates.
A Kinetic Study Of Homogeneous Bulk Polymerization Of Ethyl Methacrylate Initiated By Benzoyl Peroxide And An N, N^{\Prime} -Dimethylaniline Redox Pair, Serap Şenel, Belma Işik-Yürüksoy, Olgun Güven
A Kinetic Study Of Homogeneous Bulk Polymerization Of Ethyl Methacrylate Initiated By Benzoyl Peroxide And An N, N^{\Prime} -Dimethylaniline Redox Pair, Serap Şenel, Belma Işik-Yürüksoy, Olgun Güven
Turkish Journal of Chemistry
The homogenous bulk polymerization of ethyl methacrylate (EMA) was studied using benzoyl peroxide (BPO) and an N,N^{\prime}-dimethylaniline (DMA) redox pair with the dilatometric method. The half-order dependence of the polymerization rate upon both the BPO and DMA concentrations was obtained. The overall activation energy of the polymerization was found to be between 32.3-55.3 kJ/mole for different initial molar ratios of the redox pair. A retaring effect was observed at lower polymerization temperatures for low concentrations of BPO. The formation of reddish colored polymers at higher DMA concentrations was explained by the adsorption of adduct formed between DMA radicals.
Crystal Structure Of Tris(2-Hydroxyethyl)Ammonium Bromide, Veysel T. Yilmaz, Hasan İçbudak, Halis Ölmez, R. Alan Howie
Crystal Structure Of Tris(2-Hydroxyethyl)Ammonium Bromide, Veysel T. Yilmaz, Hasan İçbudak, Halis Ölmez, R. Alan Howie
Turkish Journal of Chemistry
The crystal structure of tris(2-hydroxyethyl)ammonium bromide, [HN(CH_{2}CH_{2}OH)_{3}]Br, was determined as rhombohedral by single crystal X-ray diffractometer. The final R value was found to be 0.032 for 576 observed reflections. The crystal consists of layers of hydrogen-bonded cations, [HN(CH_{2}CH_{2}OH)_{3}]^{+} and anions, Br^{-}. Within a layer every cation donates and every anion accepts three hydrogen bonds. In the cation, trifurcated intramolecular hydrogen bonds are formed due to the surrounding of the hydrogen atom bonded to the N atom by the 2-hydroxyethyl groups.
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Turkish Journal of Chemistry
^{31}P-NMR spectroscopy was used to study the kinetics of the chelate ring-closure reaction in CR(CO)_5 (DPPM) where DPPM is bis (diphenylphosphino) methane. DPPM is potentially a bidentate ligand, but in this complex it is coordinated to the transition metal in a monodentate fashion and therefore can undergo chelation. The thermal chelate ring-closure reaction was carried out in an NMR sample tube at a constant temperature and the course of the reaction was quantitatively followed by taking ^{31}P-NMR spectra in appropriate time intervals. Kinetic results have shown that the chelate ring-closure reaction of Cr(CO)_5 DPPM is of zero-order. Activation parameters were …
The Effects Of Polyacrylic Acid/Polypyrrole Composite Coating On Photocorrosion And Photoactivity Of Pyrite Electrodes, A. Sezai Saraç, Belkıs Ustamehmetoğlu, Esma Sezer, Candan Erbi̇l
The Effects Of Polyacrylic Acid/Polypyrrole Composite Coating On Photocorrosion And Photoactivity Of Pyrite Electrodes, A. Sezai Saraç, Belkıs Ustamehmetoğlu, Esma Sezer, Candan Erbi̇l
Turkish Journal of Chemistry
Electrically conducting polyacrylic acid (PAA)/Polypyrrole (PPy) composite films were prepared by electrochemical polymerization of pyrrole on PAA which was electrocheimically adsorbed on natural and synthetic pyrite ( FeS_{2}) electrodes. The application of such polymer coating on pyrite, which is one of the semiconducting materials for solar applications, shows almost total protection against corrosion and can improve the photoactive character of the electrode. Addition of Ce(IV) ammonium nitrate into this system improved the photoactivity of the PAA/PPy composite. The composite polymer has higher photoconductivity than the pure PPy, because of the doping effect of anions on the PPA/PPy composite.
The Effect Of Metal Loading On The Adsorption Parameters Of Carbon Dioxide On Coprecipitated Nickel-Alumina Catalysts, A. Erhan Aksoylu, A. Nilgün Akin, S. Gönenç Sunol, Z. İlsen Önsan
The Effect Of Metal Loading On The Adsorption Parameters Of Carbon Dioxide On Coprecipitated Nickel-Alumina Catalysts, A. Erhan Aksoylu, A. Nilgün Akin, S. Gönenç Sunol, Z. İlsen Önsan
Turkish Journal of Chemistry
A coprecipitation method has been developed and modified for the preparation of nickel-alumina catalysts having metal loadings in the 0-25 wt\% Ni range. The effect of metal loading on CO_{2} adsorption was investigated under isothermal chromatographic conditions using an elution technique in the temperature range 483-533 K. Average enthalpies of adsorption were determined using the isosteres obtained from the experimental adsorption isotherms. The isotherms were also fitted to the Langmuir equation for the evaluation of adsorption equilibrium coefficients, Gibbs free energies, average adsorption enthalpies and entropies. Keywords: nickel-alumina, coprecipitated nickel-alumina, CO_{2} adsorption
Validity Of A Linear Estimator For The Total \Pi-Electron Energy Of Alternant Hydrocarbons, Lemi Türker
Validity Of A Linear Estimator For The Total \Pi-Electron Energy Of Alternant Hydrocarbons, Lemi Türker
Turkish Journal of Chemistry
The validity of a linear topological estimator formula which possesses a slope k such that 0
The Concept Of Molecular Similarity And The Angle Of Total \Pi-Electron Energy, Lemi Türker
The Concept Of Molecular Similarity And The Angle Of Total \Pi-Electron Energy, Lemi Türker
Turkish Journal of Chemistry
The concept of molecular similarity is developed and a novel similarity index based on the cosine of the angle of total \Pi-electron energy is proposed to interrelate structural variations to operant properties of molecules isoconjugate with alternant hydrocarbons.
The Mechanism Of The Photoprotolytic Reactions Of Some Oxyazomethine Compounds, Lubov Efimovna Zelt'ser, Milan B. Bastic, Ljubinka V. Rajakovic
The Mechanism Of The Photoprotolytic Reactions Of Some Oxyazomethine Compounds, Lubov Efimovna Zelt'ser, Milan B. Bastic, Ljubinka V. Rajakovic
Turkish Journal of Chemistry
The kinetic spectral study of the photoprotolytic reactions of oxyazomethine molecules was performed. It was established that the deprotonation reactions of oxyazomethines proceed with the participation of electronically excited molecules and are characterized by parameters which differ to basic state reactions.
Distribution Of Ce (Iv) Species In Hno_{3}-Hcio_{4} Media And Determination Of Stability Constants Of The Nitrato Complexes, Seval Bayülken, A. Sezai Saraç
Distribution Of Ce (Iv) Species In Hno_{3}-Hcio_{4} Media And Determination Of Stability Constants Of The Nitrato Complexes, Seval Bayülken, A. Sezai Saraç
Turkish Journal of Chemistry
In this paper, the distribution of cerium (IV) species depending on the charges of nitric acid-perchloric acid concentration at constant ionic strength (I=1.0) was investigated. Cerium (IV), being a strong oxidant, was utilized for investigating the oxidation kinetics of some amino acids. Knowing the distribution of cerium (IV) species is beneficial for better understanding this type of kinetics. Distribution of cerium (IV) species in aqueous media was studied by measuring the total optical absorbance of cerium (IV) species in different nitric acid-perchloric acid mixture solutions. The stability constants (K_{1} and K_{2}) of the nitrato cerium complexes were determined spectrophotometrically from …
Automation Of Dipole Moment Measurements Using Microprocessor Controlled System, Nil Tarim, Hakan Kuntman, Ayten Kuntman
Automation Of Dipole Moment Measurements Using Microprocessor Controlled System, Nil Tarim, Hakan Kuntman, Ayten Kuntman
Turkish Journal of Chemistry
A microprocessor controlled instrument that can be used in physical chemistry research laboratories has been designed and constructed. The intended use is the measurement of the dipole moment and determination of the temperature dependency of the dipole moment for polar substances, especially for macromolecules. Measurement techniques with conventional dipolmeters require fine adjustments and measurements which seem to be very tedious and time consuming. Provided automation enables very frequent measurements with a step of 1^{\circ}C and disallows any user-oriented error. The dielectric constant measurement is performed within an accuracy limit of less than \pm 0.001. Furthermore, the equipment designed provides the …
Polyelectrolytes In Immunology: Fundametals And Perspectives, Mehmet I. Mustafaev
Polyelectrolytes In Immunology: Fundametals And Perspectives, Mehmet I. Mustafaev
Turkish Journal of Chemistry
Physico-chemical criteria for the construction of artifical immunomodulators and immunogens(and vaccines) on the basis of synthetic polyelectrolyte(PE) and polyelectrolyte complexes(PEC) with low molecular weight ligands and protein (and polysaccharide) antigens are considered. The role of electric charge, chain length, conformation, hydrophobicity, polydispersity and supramolecular structure in the immunomodulating activity of PE(PEC) and the conditions facilitating the transformation of their suppressor capacity into immunostimulating one in the same polymerhomologues series are discussed. A structure-function relationship of immunogenicity of PE(PEC), a structural model of an artificial polymer- subunit immunogen and some practical applications of them as valuable tools in theoretical immunological studies …
Enantioselective Synthesis Of 4-Hydroxy-3-(3-Oxo-1-Phenyl Butyl)- 2h-1-Benzopyran-2-One (Warfarin), Ayhan S. Demi̇r, Cihangir Tanyeli, Volkan Gülbeyaz, Hülya Akgün
Enantioselective Synthesis Of 4-Hydroxy-3-(3-Oxo-1-Phenyl Butyl)- 2h-1-Benzopyran-2-One (Warfarin), Ayhan S. Demi̇r, Cihangir Tanyeli, Volkan Gülbeyaz, Hülya Akgün
Turkish Journal of Chemistry
Oral anticoagulant Warfarin (4-hydroxy-3-(3-oxo-1-phenyl butyl)-2H-1- benzopyran-2-one) is synthesized in optically active form starting from 4- hydroxycoumarin via formation of optically active enamines followed by Michael addition reaction with benzyliden acetone at low temperature. Different amines gave 17-68\% ee and the chemical yield was 22-71\%, depending on the reaction conditions and the structure of chiral amines.
The Determination Of Some Heavy Metal Cations By Tlc/Photodensitometry, Şahin Savaşçi, Mehmet Akçay
The Determination Of Some Heavy Metal Cations By Tlc/Photodensitometry, Şahin Savaşçi, Mehmet Akçay
Turkish Journal of Chemistry
The samples having complex matrices were analyzed for some heavy metal cations by using a thin layer chromatography/photodensitometry (TLC/PD) system. The rock samples were dissolved by suitable methods. Nickel, Cobalt and Copper were dedected and analyzed by photodensitometric comparison of corresponding spots of samples with those of standards. The results of the same samples and standards were compared with those obtained by atomic absorption measurements. Our results are comparable with the results of flame atomic absorption measurements. The precision of TLC method was calculated to be 9.4\% as relative standard deviations depending on 17 replicate measurements. The accuracy of TLC …
Molecular Structure Of 2'-Hydroxy-3'-Methoxy-5'-Allyl -4-Methylazobenzene, Veysel T. Yilmaz, Selami Şasmaz, İsmail E. Gümrükçüoğlu, R. Alan Howie
Molecular Structure Of 2'-Hydroxy-3'-Methoxy-5'-Allyl -4-Methylazobenzene, Veysel T. Yilmaz, Selami Şasmaz, İsmail E. Gümrükçüoğlu, R. Alan Howie
Turkish Journal of Chemistry
2'-hydroxy-3'-methoxy-5'-allyl-4-methylazobenzene was synthesized in two steps: 4-methylbenzenediazonium chloride was prepared by the reaction of 4- methylaniline, HCL and NaNO_{2}, and was then reacted with eugenol to give 2'-hydroxy-3'-methoxy-5'-allyl-4-methylazobenzene. The molecular structure was identified by UV/VIS, IR, ^{1}H-NMR and elemental analysis. The crystal structure was determined as monoclinic by single crystal X-ray diffraction technique. The final R values was found to be 0. 078 for 1065 observed reflections. The structure consists of isolated molecules with van der Waals contacts and the molecule is essentially planar in the solid state. There is a strong intramolecular hydrogen bond in which the hydroxyl group …
Synthesis Of Some Pyrazolo-Pyridazine Compounds, Adem Önal, Yunus Akçamur, Behzat Altural
Synthesis Of Some Pyrazolo-Pyridazine Compounds, Adem Önal, Yunus Akçamur, Behzat Altural
Turkish Journal of Chemistry
Addition of {\bf 1} to two moles of phenylhydrazine gives 1,2,4,6- tetraphenyl-(2,3-d)-pyrazolo-5,6-pyridazine-7-one {\bf 4} isomer compound 1, 2,3,5-tetraphenyl-(2,3-d) pyrazolo-5,6-pyridazine-7-one {\bf 5} of {\bf 4} was synthesized by the reaction of {\bf 2} with phenylhydrazine. 3,4- Diphenyl-(2,3-d)-pyrazolo-(1H,6H)-pyridazine-7-one {\bf 6} was also obtained in two different ways. Reaction of {\bf 1} and 4-benzoyl-5 phenyl- furan-2,3-dione {\bf 3} with hydrazinium hydrate furnished compound {\bf 6}. The structures of {\bf 4,5} and {\bf 6} were determined by the ^{13} C- NMR, IR spectra and elemental analysis. These new isomer and condensed compounds synthesized in this study are important for heterocyclic chemistry.
Cycloaddition Reactions Of Dichloroketene To Allyl Ethers, Hülya Şenöz, Süleyman Yildirir
Cycloaddition Reactions Of Dichloroketene To Allyl Ethers, Hülya Şenöz, Süleyman Yildirir
Turkish Journal of Chemistry
Allyl ethers reacted with dichloroketene by [2+2] Cycloaddition to produce 2,2-dichlorocyclobutanones structure of products were determined by IR, NMR, GC MS tecniques.
Fixed Bed Pyrolysis And Hydropyrolysis Of An Immature Type I Turkish Oil Shale, Murat Çitiroğlu, Selma Türkay, Zeynep Işık Cepni̇, Colin Edward Snape
Fixed Bed Pyrolysis And Hydropyrolysis Of An Immature Type I Turkish Oil Shale, Murat Çitiroğlu, Selma Türkay, Zeynep Işık Cepni̇, Colin Edward Snape
Turkish Journal of Chemistry
A number of different pyrolysis procedures were investigated in order to achieve higher oil yields from an immature type I oil shale than obtained under static retorting conditions. Both nitrogen and steam gases increased yields as inticipated: Steam achieving comparable yields to nitrogen but at much lower gas velocities. The composition of the tars varied considerably, steam increasing the concentration of alkenes. In coprocessing the oil shale with a Turkish lignite in the Heinze retort, oil yields were higher than predicted principally due to extraction of the lignite by pyrobitumens obtained from the oil shale. Fixed bed hydropyrolysis of the …
Synthesis Of 2[1'(3',5'-Disubstituted Pyrazolyl) Methyl]5-Phenyl Amino-1,3,4-Thiadiazoles And 1,2,4-Triazoles As Potential Therapeutic Agents, Roshan Ahmad, M. Zia-Ul-Haq, Rukhsana Jabeen, Helmut Duddeck
Synthesis Of 2[1'(3',5'-Disubstituted Pyrazolyl) Methyl]5-Phenyl Amino-1,3,4-Thiadiazoles And 1,2,4-Triazoles As Potential Therapeutic Agents, Roshan Ahmad, M. Zia-Ul-Haq, Rukhsana Jabeen, Helmut Duddeck
Turkish Journal of Chemistry
A complete synthesis of 2[1'(3', 5'-disubstituted pyrazolyl) methyl] 5- phenyl-1,3,4-thiadiazole V(a-b) and 1,2,4-trizole VI (a-b) is reported. Cyclocondensation of \beta-diketones with etylhydrazino acetate hydrochloride yielded ethyl 3,5-disubstituted pyrazolyl acetate II(a-c) which on treatment with hydrazine hydrate resulted in the formation of their hydrazide derivatives III(a-c). These hydrazides, when treated with phenyl isothiocyanate, gave thiosemicarbazide derivatives IV(a-c), which were cyclised in the presence of con. H_{2}SO_{4} and NaOH to give V(a-b) and VI(a-b), respectively.
Extraction Of Dyestuff From Onion (Allium Cepa L.) And Its Application In The Dyeing Of Wool, Feathered-Leather And Cotton, Adem Önal
Turkish Journal of Chemistry
In this study, the total amount of dyeing substances present in onion (Allium cepa L.) was determined by using the extraction method. The extracted substanc were used in the dyeing of woollen strips, feathered- leather and cotton. Dyeing conditions and other characteristics were determined and the repeatable specifics were evaluated for these processes so that ligh fast colours could be obtained.
Extraction Of Dyestuff From Madder Plant ( Rubia Tinctorum L.) And Dyeing Of Wool, Feathered-Leather And Cotton}, Adem Önal
Turkish Journal of Chemistry
In this study, the total amount of dyeing substances present in {\it Rubia tinctorum L}. was found by using the extraction method and then separated in column. All of the dyeings were carried out with red component alizarin (1,2-dihydroxyanthraquinone). Dyeing conditions and other characteristics were determined and in most cases high fast colours were obtained.
Circular Dichroism Studies Of Complexation Of Antibiotic (+)- Cephradine With Cr(Iii), Co(Ii) And Ni(Ii) In Methanol: Water (80:20) Solution, Nasir Ahmad, Javed Safder, Christy Munir
Circular Dichroism Studies Of Complexation Of Antibiotic (+)- Cephradine With Cr(Iii), Co(Ii) And Ni(Ii) In Methanol: Water (80:20) Solution, Nasir Ahmad, Javed Safder, Christy Munir
Turkish Journal of Chemistry
Circular dichroism (CD) studies have been utilized to investigate complexation of antibiotic (+)-cephardine with Cr(III), Co(II) and Ni(II) ions in methanol: water (80:20 v/v) solution. The optimum conditions of pH, stoichiometry and time for achieving equilibrium for maximum complexation in these systems are determined. The CD spectra of these complex ions consist of 2-3 Cotton bands between 16,129-25,994 cm^{-1} with differential absorptivity 0.0046-0.428 deg. L mol^{-1} cm^{-1} and bands are assigned to electronic transitions. The formation constants of these complexes in mixed solvent are reported.
Extractive Spectrophotometry Of Palladium(Ii) With 3,4,5- Trimethoxybenzaldehyde Thiosemicarbazone, A. M. A. Khader, K. S. Prasad
Extractive Spectrophotometry Of Palladium(Ii) With 3,4,5- Trimethoxybenzaldehyde Thiosemicarbazone, A. M. A. Khader, K. S. Prasad
Turkish Journal of Chemistry
The extractive spectrophotometric determination of palladium(II) using 3,4, 5-trimethoxybenzaldehyde thiosemicarbazone (TBTSC) is discussed in this study. It forms an intense yellow-coloured chloroform-soluble complex with paladium(II) in an acidic medium. The molar absorptivity at 370nm is 8.35x 10^{4} 1. mol^{-1} cm^{-1}. The complex system conformed to Beer's Law up to a concentration limit of 12 ppm. The Sandell's sensitivity was 8. 57 ng. cm^{-2}. The interference of various ions was studied, and palladium(II) in its alloy compositions was analysed.
Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq
Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq
Turkish Journal of Chemistry
The preparation of optically active camphorsulphonylbenzimidazole {(\bf 1)}, a mixture of regioisomeric 5-nitro- {\bf (2A)} and 6-nitro-{\bf (2B)} camphorsulphonylbenzimidazoles, 5-nitro-{\bf (3A)} and 6-nitro-{\bf (3B)} 2- methyl camphorsulphonylbenzimidazoles is described. In this study the structure of the purified camphorsulphonylbenzimidazoles {\bf 1, 2B, 3A} and {\bf 3B} was confirmed by their mass and ^{1}H NMR spectral analysis. The specific rotation of each pure compound is also reported.
A Comparison Of Adsorption Isotherms Of Crosslinked Poly(N-Vinylpyrrolidone)/Basic Brown 1 Binding System, Dursun Saraydin, Erdener Karadağ
A Comparison Of Adsorption Isotherms Of Crosslinked Poly(N-Vinylpyrrolidone)/Basic Brown 1 Binding System, Dursun Saraydin, Erdener Karadağ
Turkish Journal of Chemistry
In this study, the binding of a basic dye such as basic brown 1 [BB 1] onto a crosslinked poly(N-vinylpyrrolidone) [CPVP] was investigated. Adsorption of the azo dye onto the CPVP was studied by the batch adsorption technique at 25^{\circ}C. In adsorption experiments a Langmuir type (L) adsorption was found with respect to the Giles classification system. Binding parameters such as initial binding constant (K_{i}), equilibrium constant {\it (K)}, monolayer coverage (n), site-size (u), and maximum fractional occupancy (\hat{\theta}), and thermodynamic parameters such as heat of adsorption (\Delta H), free energy of adsorption (\Delta G) and entropy of adsorption (\Delta …
The Facile Synthesis Of Cyclopentanoid Antibiotic Kjellmanianone, Ayhan S. Demi̇r, Cihangir Tanyeli̇, Volkan Gülbeyaz, Hülya Akgül
The Facile Synthesis Of Cyclopentanoid Antibiotic Kjellmanianone, Ayhan S. Demi̇r, Cihangir Tanyeli̇, Volkan Gülbeyaz, Hülya Akgül
Turkish Journal of Chemistry
The synthesis of cyclopentanoid antibiotic Kjellmanianone is described in this study. The C-acylation of lithium enolates of 3-Methoxycyclopentenone by N-carbomethoxyimidazole or methylcyanoformate \beta-ketoester, which when oxidized with Mn(III) acetate produces kjellmanianone in good yield.